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Re: Antenna Questions



<snip>

> A CP antenna is certainly best as that's what the satellite uses.  But
> again, it's not necessary.  You'll just lose some gain in the overall link
> equation, but a standard yagi is far better than an egg beater, I think.

<snip>


Are there any studies or data that show the effects (attenuation)
when one of 2 circular polarized antennas with compatible sense
are off-pointed at various angles ?

This would produce what I believe to be an elliptical pattern, but
is  there any data to support the perceived attenuation at the
receiving station provided it is pointed at the off-pointed CP
antenna.

I have used both linear and CP antennas.  In one instance, my
linear polarized antenna worked better than a local station
using a CP antenna of the same boom length into AO-10.
While this may not be the standard, it was notable because
the difference was obvious to both stations.

What if the spacecraft antenna where at such an angle it
produced an elliptical signal that was perceived at the receiving
end as a vertically polarized signal (rotation in the vertical plane
relative to the receiving station).  Would the vertical linear
polarized antenna receive it better or would a CP antenna
receive it better ?  Let's say the CP gain and the linear gain
numbers are identical.  There are a lot of variables here, but I
am looking for the concept.

I am not looking to debate CP versus linear, since I understand
the Physics.  What I am looking for is if there are any models
showing attenuation and perceived rotation pattern between CP
antennas when one is off-pointed from the other at various angles.
I am looking for actual performance from measured data if
someone can point me in the right direction.


Happy Holidays,

Tim - N8DEU
Huntsville, Alabama


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